This Mens Extra Heavy sock is the warmest sock from the Smartwool range & designed as a mens mountaineering sock but suitable for keeping feet warm anywhere. The heavyweight sock features WOW technology & so has a reinforced sole giving maximum comfort & durability whilst out on hard walks & long hikes. The flat knit toe seam stops any irritation occuring around the toes & this sock will always stay in place thanks to the Smart Wool fit system (so there won't be any bunching inside your hiking boot). Features WOW technology in reinforced sole for maximum comfort & durability 2X1 rib knit cuff Sizing clearly indicated on the sock Flat knit toe seam Smart Wool fit system with arch & ankle support Specifications Height: Crew Fabric: 80% merino wool, 19% nylon, 1% elastane Cushioning: Extra heavy full cushioned